The present invention relates to DC to high frequency switching using coaxial lines and connectors, and more particularly to a high frequency coaxial switch which has compensated transitions from coaxial to microstrip to stripline and back.
Current high frequency switches, such as the Model S-2813 made by RLC Electronics of New Jersey, use stripline contacts to the coaxial center conductors directly. These devices are effective up to 18-26 GHz, but attempts to extend this technology up to 40+ GHz have not been successful due to the small size of the components at that frequency range. There are some coaxial connectors designed to operate in the 40+ GHz range, such as the K connector manufactured by Wiltron of Mountain View, Calif. The center conductor of such connectors is approximately 0.012" in diameter which results in a very small surface contact area for a stripline switch.
Another type of high frequency switch is described in co-pending U.S. patent application Ser. No. 728,130 filed Apr. 29, 1985 by the present inventors entitled "Integrated Pad Switch". This switch has the contacts embedded in a dielectric substrate and requires a smooth hybrid substrate, such as polished quartz which is not suitable for high power attenuator applications due to the low thermal coefficient of conduction. The dielectric substrate introduces some insertion loss at high frequencies.
Therefore, what is desired is a high frequency coaxial switch which is reliable, has low insertion loss and has improved power handling capabilities.